Grey respiratory mask having black lines of demarcation



FIG. 1 is a perspective view, showing the new design for a grey respiratory mask having black lines of demarcation;

FIG. 2 is a front view thereof;

FIG. 3 is a left side view thereof, the right side being a mirror image of the left side view;

FIG. 4 is a rear view thereof;

FIG. 5 is a top view thereof; and,

FIG. 6 is a bottom view thereof.

The horizontal dashed broken lines on the surface of the mask indicate the color grey. The black demarcation lines indicate the color black. The dot-dot dashed broken lines circumscribing the mask represent the boundary of the claimed design. The remaining broken lines represent the portions of the design that form no part of the claim. 

The ornamental design for a grey respiratory mask having black lines of demarcation, as shown and described. 